Disk seal tube



R. M. BOWIE DISK SEAL TUBE Jan. l2, 1954 Filed June 24, 194e INVENTOR.

ROBERT M 50W/ /L//S /TTORNEY Patented Jan. 12, 1954 DISK SEAL TUBERobert M. Bowie, Manhasset, N. Y., assignor to Sylvania ElectricProducts, Inc., a corporation of Massachusetts Application June 24,1946, Serial No. 678,825

14 Claims. (Cl. 315-5) The invention relates to a tube mounting, par-f"fltics will be pointed out where pertinent to a full ticularly to themounting of tubes of the discseal types.

Certain types of electron devices, generally related to the tron family,such as the magnetron and klystron, employ electron tubes which aredesigned to operate in close proximity to cavity resonators and, tofacilitate electrical connections thereto, may be constructed withdisc-seal electrodes. rIhe mounting of a disc-seal tube within such anelectron device has been a delicate as well as a complicated operation,particularly from the standpoint of easy accessibility for repair orreplacement purposes.

A principal object of the invention is to provide improved means andmethod of mounting a discseal type tube within the cavity resonator of acavity type electron device, such as an oscillator, an amplier, or thelike.

Another object is the provision of an arrangement for improving theradio frequency contact between the cavity resonator and means whichsupport the tube within the cavity.

A special object of the invention is the provision of simplified meansfor clampingthe smaller disc shaped connector of a disc-seal tube intothe cavity of a resonator.

` Other objects of the invention have to do with novel features ofconstruction which will become apparent as the description proceeds.

Fig. 1 is a sectional view of an electron device` having a radial cavityresonator in which a discseal tube is mounted in accordance with thepresent invention; f

Fig. 2 is a longitudinal sectional, view of a different type of electrondevice having a disc-seal tube mounted in a concentric line cavityresonator;

Fig. 3 is an enlarged fragmentary sectional view taken on the line 3-3of Fig. 2, showing a sheet metal disc spun over the edges of a shoulderof a collar member; and

Fig. 4 is a similar View showing a preferred form of the constructionillustrated in Fig. 3.

In the drawing only suicient structure is shown of the electron deviceas is required to illustrate the invention. I have elected to disclosethe invention as applied to a magnetron `and a klystron in conjunctionwith a radial cavity resonator and a concentric line resonator,respectively. For the sake of convenience, in describing the two formsof cavity resonators illustrated herein, similar reference charactersindicate corresponding parts as far as practical. However, diierences instructural characterisappreciation of the invention.

Referring particularly to Fig. l, the reference character I designatesgenerally a radial cavity resonator which may be employed with amagnetron. As is Well known a magnetron may be a high-vacuum cavityoscillator, and at least one conventional form of a magnetron has adisc-seal tube mounted in the cavity resonator. In the past a splitcavity has generally been used in mounting the disc-seal tube within thecavity because such tubes were often made with both discs of the samediameter. Although the provision of one smaller disc would havefacilitated insertion into an unsplit (non-segmental) cavity, difcultywould have been encountered in firmly clamping the smaller disc inplace. The present invention contemplates primarily means for firmlyclamping the smaller disc electrode into the cavity resonator. Undermost circumstances this operation is very trying, and any constructionwhich simplifies the operation may be regarded as an advance in the art.

Referring to Fig. 2, there is disclosed an electron device of theconcentric line cavity type such as represented by a klystron. Thisdevice is also a high vacuum oscillator employing a cavity resonator,but of the type known as a concentric line cavity. The cavity resonatorsof these two type oscillators, i. e. magnetron and klystron, as hereinshown, are of different construction but generally they functionsimilarly. In. those respects in which the resonators functiondifferently, they have no bearing on the present invention.

With this general understanding of the application of the presentinvention, reference may again be had to Fig. l. The disc-seal tube 2has a plurality of electrodes (not shown) some of which are providedwith radially disposed discshaped terminals. According to past practicethese terminals were of the same diameter and severally clamped into theinner margin of the cavity resonator. In the present construction one ofthese terminals comprises a metal disc 3, which is suitably sealedthrough the envelope of the tube 2, and connected to an electrodethereof. On one end of the tube 2 there is provided an external collarstructure 4 having a cylindrical body portion provided with threads 6. Asecond sheet metal disc I, which may be copper, is also sealed throughthe envelope and joined to the collar 4. The manner in which the disc 'Imay be spun over the edges of a flange on the collar 4 to improve theradio frequency contact between the disc and the adjacent conductor ofthe cavity resonator I will be more fully explained hereinafter inconnection with Figs. 3 and 4. It will be noted that the terminalscomprising the discs 3 and 'I are concentrically disposed andlongitudinally displaced along the axis of the tube I, and are ofdifferent diameters, disc 'I being of smaller diameter than-disc 3. Itwill also be noted that the spacing of discs 3 and 'I, With respect toeach other, must conform to the depth of the cavity resonator. Thereason for this latter feature will become obvious as the descriptionproceeds.

It will be noted from the drawing that the cavity resonator I is of aone-piececonstruction. Referring particularly to Fig.1,.'th'eresonato1nis primarily a fiat hollow cylinder having end walls 8and 9 provided with concentrically arranged circular apertures II andI2, respectively. The aperture II is of larger diameter than theaperture I2, the aperture I I being formed on the outer orflefthand endwall of the resonator, and the aperture i2 being formed on theinnerorright hand end wall thereof. ,Surrounding the apertures II and I2are shoulders Iand M respectively, formedcontiguous to the margin vofthesaid apertures. rIlhese shoulders constitutemeans for concentricallylOQatlg the vdisc-seal .tube 2 within the cavity resonator I, thearrangement being that theyact asia bearing surface for the edges ofdiscs 3 and ,'I. That is to say, the diameters of the apertures II andI2 correspond substantially to the diameters vof discs 3 and `'1,Yrespectively, so that Ythe peripheral edges ofsaid discsare adapted toregister with theshoulders I3 and I4,.respectively.

The'disc 'I, being of smaller diameter than the aperture ISI passeseasily therethrOllgh, and is adapted to vregister withthe shoulder I4.The

isc Iv is retained on the shoulder .M byrneans of an'internally threadednut I5, the threads of which .engage the external threadsl on the collar4. Bytightening the nut I5 rthedisc 'inlay be drawn into intimateContact withthe .shoulder I4. As mentioned above, the copper disc 'I maybe spun` over the edges of a flange on collar i and isthus placed indirect contact With theend wall of the Cavity resonatorl So thattho,shoulder .M abuts against the spun disc I rather than ,dire'ctlyagainst the collarA.. By virtue ofthis construction the radio frequencycontaetbetweenthe disc and the cavity resonator isfrnerepositive, andfor obvious .reasons constitutes van improved connectionfortheresonator.n

.The disc 3in accordance with the. eonstruction illustrated in Fig. l,is retained upon the shoulder I ,Bbythe ring I6 having a dependingflange I1 formed upon the peripheral edge of the ring I6. The flange IJntssnugly into the apertures I.I and issecured in place by screws I0which pass throughholes `in the ring .i6 and engages suitable threadsformed in the outer surface of end wall 8 of the resonator I. Themounting of the discseal tube `2 within the resonant cavity may beaccomplished by inserting the smaller end of the tube through theapertures II and I2. The nut I5, when tightened, holds the collar 4 inposition, and ring IB when properly positioned with respect to thethreaded holes on the adjacent wall of the resonator, secures thediScSyinipIace. It is obvious that in accordance with this construction,to remove .the tube 2 .from the cavity resonator, all that is requiredis to loosen the screws I0 and the nut I5. This frees the tube 2 of itsclamping means andpermits the ready Withdrawal thereof.

Referring to Fig. 2, it will be noted that the general construction of acavity resonator of the concentric line type is basically diiferent,although having fundamentally the same operating principles as a radialcavity resonator. A concentric line cavity resonator I, according tostandard construction, embodies an inner conductor I8, an.outerconductor 2i}-,1and a shortingV plunger I9 which islongitudinally-slidable between the inner and outer conductors to permitadjustment of the length of the resonator Yandhence of its resonantfrequency.

is illustrated as .mounted partially .within the resonator I is aAklystron having an elongated tubular envelope The electron tube whichshewnpassing out through-the center conductor i8.. At thefother end thetube isprovided Witha base Ehaving pins 2,1 connected. to other leadssealed through section. Z-I ,of the envelope.V

When the tube is mounted ,in the resonator, sections 22 vand ,23 of theenvelope, lwith disc 'I sealed between them,-pass throughfthe openend ofthe Youter .conductor 2B, `the aperture .being large, enough` to admitdisc is' -but having` a. ShOul-- der I3 against which thelargerdiscabuts-when the tube isfully inserted. This-insertion viseompleted Vbyscrewing threads 6 .of Vcollar vII into threads .2.8 .providedrontheinside of-inner-,conductor I8. The disc 'I may be drawn `-.snuglyguyglagainstshoulder lAon-theinner conductor 1,8,

l while the disc .3 will simultaneously abut against l shoulder .I3 `on'the outer conductor. .Good VcondiseS Vforms no part Yoi the invention,it being' immaterial'whether the device is a threaded ,nut

as kin Fig. 2,a clamping ring I6, as in. Fig. l,

o r any othersatisfaotory arrangement.

The manner 'n vwhich .threaded collar ,4 is

joined to disc 'I so that the inner conductorabuts"l over the'edgesofwhich the disc Ifisfspun '.'Ihe' inner conductor I8 thus-extends along,thefsuriace' ofthe disc', .while shoulder I4 on Athe inner surface o fthe inner conductor-.abuts against -'the disc. If kthe disc is notspun4overthe flange T 5 on the V,threaded collar, `but `4merely ,extendedalong oneV side `of thek hangs, Y.the inner conductor L8 will touch fthedanse. ;5 instead .of the disc directly, and .currents passing :between`the` disc and the innerconductor of the cavity will be required to passfrom the disc to the collar and thence to the inner conductor of theresonator, traversing two contact surfaces instead of one.

Since the sectional View of Fig. 3 shows a portion of the interior ofthe tube, grid electrode 3! appears attached to the inner edge of disc1.

A preferred modification of this construction is shown in Fig. 4. Theflange 5 on threaded collar 4 `is extended so that the disc spun overthe flange forms an outer surface which has substantially the samediameter as the inner conductor I8 of the cavity resonator. The spinningof the disc over the edges of the flange is continued so that the entireend surface of the inner conductor may abut against the disc. Arelatively smooth and continuous surface is thus formed for the wall ofthe cavity resonator. In this case the shoulder I4 is unnecessary andmay be omitted.

In the arrangement of Figs. 1 and 2 a coupling loop 32 is provided fortransferring radio frequency power from the cavity resonator to acoaxial line 33.

Although I have shown and described particular embodiments of myinvention I do not vdesire to be limited to the embodiments set forth.It is my intention to cover all such modincations as come within thescope of the appended claims.

What I claim is:

1. A mount construction for supporting a discseal tube within theresonant cavity of an eleotron device comprising a cavity resonatorhaving opposing apertures of different diameters formed in the end wallsof the resonator, a discseal tube having a number of electrodes providedwith terminals concentrically disposed along a common axis, saidterminals being discshaped and substantially corresponding in size andspacing to the arrangement of said apertures, a collar structure securedto said tube for clamping the smaller of said terminals over the smallerof said apertures, and a ring construction for clamping the larger ofsaid terminals over the larger of said apertures, said collar and ringconstruction being designed to make the tube easily demountable from thecavity resonator.

2. A mount yconstruction for supporting a discseal tube within theresonant cavity of an electron device comprising a cavity resonatorhaving opposing apertures of different diameters formed in the end wallsof the resonator, terminals adapted to fit said apertures, one of saidterminals comprising a threaded collar attached to one end of the tubeand having a flange portion, another of said terminals comprising a discspaced from said collar and corresponding in diameter to the larger ofsaid apertures, means Within the cavity resonator for supporting saidcollar and said disc, and means for retaining said collar and said discon said supporting means, said retaining means for the disc comprising aclamping ring member, said clamping ring member being mounted exteriorlyou the cavity resonator, said retaining means for the collar comprisinga nut for engaging the threads on the collar and drawing the angeportion thereof against a shoulder surrounding the smaller of saidapertures.

3. A mount construction for supporting a discseal Within the cavityresonator of an electron device, comprising a cavity resonator havingopposing apertures of diierent diameters formed in the end walls of theresonator, a shoulder shoulders, a collar secured to said tube forclamping the smaller of said terminals onto the shoulder of said smalleraperture, a ring member for clamping the larger of said terminals ontothe shoulder of the larger of said apertures, and means for retainingsaid ring member in engagement with said shoulders.

4. The mount construction set forth in claim 3, wherein the means forretaining the collar in place comprises a nut adapted to engage thethreads on the collar and fasten the latter onto the supporting shouldersurrounding the smaller aperture, and the means for retaining the ringmember in engagement with the shoul-der surrounding the larger aperturecomprising a threaded connection between the ring member and the outerend wall of the cavity resonator.

5. A mount construction for supporting a discseal tube within theresonant cavity of an electron device comprising a cavity resonatorhaving opposing apertures of different diameter, the larger apertureconstituting an entrance to the resonator and the smaller apertureconstituting an exit therefrom, a disc-seal tube'designed to be insertedin the cavity resonator, said tube having disc terminals adapted toregister with said apertures, and means for retaining said terminals inengagement with said apertures, said retaining means comprising an innerclamping member secured to said tube, said inner clamping memberincluding a threaded collar adapted to form a butt seal with aconductive portion of said device.-

6. A mount construction for supporting a discseal tube within theresonant cavity of an electron device comprising a cavity resonatorhaving opposing apertures of different diameters,

the larger aperture constituting an entrance to the resonator and thesmaller aperture constituting an exit therefrom, a disc-seal tubedesigned to be inserted in the cavity resonator, said tube having discterminals adapted to register with said apertures, and means forretaining said terminals in engagement with said apertures, saidretaining means comprising an outer clamping member and an innerclamping member secured to said tube, said inner clamping memberincluding a threaded collar adapted to form a butt seal with aconductive portion of said device.

'7. An electron tube including an envelope, a disc terminal sealedthrough said envelope, and a threaded collar carried by said envelopeand connected to said disc terminal for urging said terminal into directcontact with a wall of a cavity resonator.

8. An electron tube including an envelope, a disc terminal sealedthrough said envelope, and means including a threaded collar forconnecting said disc to a cavity resonator, said disc being spun oversaid collar so that said disc may be placed in direct contact with acavity resonator.

9. The mount -construction set forth in claim 6, wherein the collarstructure comprises a threaded cylindrical body member having aperipheral flange portion, and a sheet metal disc terminal: Spunwer'theedeesroftsad flange n0r' tion,;-wherebythe center electrode of theresonator ,abuts against :the Spun dise rather than against the collarper se.

:71.0,- The ymount construction set forth ,in claim 2 whereinthe cavityresonator has an entrance omarger diameter .than the exitthererom, saidelli? 31H58 and Vest; providing the supporting me ns ,for the discandcollar, said arrangement making the tube'v demountable Without. zdisas-Sembling the resonator.

1;1. electron vtube including an envelope,

an ,externally vthreaded collar [surrounding said errrelope, vsaidIcollar having a flange, andi an annular terminal Sealed through saidenvelope andpbnded `over said flange- 12,V In Acombination -with ltheelectron tube of claimfhha high frequency .cavity havinga shouldergedaperture, an *interiorly threadedpart assoeiated with `said aperture,said threaded co1.- -lar-and threaded part being drawn totighten theAbeaded-over terminal iirrnly between said4 envelope, an externally.threaded collar surrounding. Said envelope, Said collar .having aflange, annular terminal sealed through said envelope and ebeaded oversaid flange, anaddie tional annular terminal of larger diameter,A thansaid beaded-,over terminal sealed through,said envelope, said additionalterminal .being on the side of said envelope opposite the threaded por-ition of said collar, acavity having two axially aligned shoulderedapertures `of different diameters, spaced apart a distancesubstantiallyequal to the distance between vthe terminals ofisaid tube,an interiorly threaded part vassociated with the aperturev of smallerdiameter and tightened on said threaded. collar to grip the kbeaded-overterminal rnily between said' ange andV the shoulder of said aperture,and another collar .to press said additional terminal against theshoullder oli the other aperture.

ROBERT 4M. BOWLE.

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